1 /*
2  * Copyright (c) 2018, 2019, 2020 Stefan Sperling <stsp@openbsd.org>
3  *
4  * Permission to use, copy, modify, and distribute this software for any
5  * purpose with or without fee is hereby granted, provided that the above
6  * copyright notice and this permission notice appear in all copies.
7  *
8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15  */
16 #include "got_compat.h"
17 
18 #include <sys/types.h>
19 #include <sys/stat.h>
20 #include <sys/queue.h>
21 #include <sys/uio.h>
22 #include <sys/mman.h>
23 #include <sys/resource.h>
24 #include <sys/socket.h>
25 
26 #include <fcntl.h>
27 #include <errno.h>
28 #include <stdio.h>
29 #include <stdint.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <limits.h>
33 #include <unistd.h>
34 #include <zlib.h>
35 
36 #include "got_error.h"
37 #include "got_object.h"
38 #include "got_path.h"
39 
40 #include "got_lib_hash.h"
41 #include "got_lib_delta.h"
42 #include "got_lib_delta_cache.h"
43 #include "got_lib_inflate.h"
44 #include "got_lib_object.h"
45 #include "got_lib_object_parse.h"
46 #include "got_lib_privsep.h"
47 #include "got_lib_pack.h"
48 
49 #ifndef nitems
50 #define nitems(_a) (sizeof(_a) / sizeof((_a)[0]))
51 #endif
52 
53 #ifndef MIN
54 #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
55 #endif
56 
57 static const struct got_error *
58 verify_fanout_table(uint32_t *fanout_table)
59 {
60 	int i;
61 
62 	for (i = 0; i < 0xff - 1; i++) {
63 		if (be32toh(fanout_table[i]) > be32toh(fanout_table[i + 1]))
64 			return got_error(GOT_ERR_BAD_PACKIDX);
65 	}
66 
67 	return NULL;
68 }
69 
70 const struct got_error *
71 got_packidx_init_hdr(struct got_packidx *p, int verify, off_t packfile_size)
72 {
73 	const struct got_error *err = NULL;
74 	enum got_hash_algorithm algo = GOT_HASH_SHA1;
75 	struct got_packidx_v2_hdr *h;
76 	struct got_hash ctx;
77 	uint8_t hash[GOT_HASH_DIGEST_MAXLEN];
78 	size_t nobj, len_fanout, len_ids, offset, remain;
79 	ssize_t n;
80 	int i;
81 
82 	got_hash_init(&ctx, algo);
83 
84 	h = &p->hdr;
85 	offset = 0;
86 	remain = p->len;
87 
88 	if (remain < sizeof(*h->magic)) {
89 		err = got_error(GOT_ERR_BAD_PACKIDX);
90 		goto done;
91 	}
92 	if (p->map)
93 		h->magic = (uint32_t *)(p->map + offset);
94 	else {
95 		h->magic = malloc(sizeof(*h->magic));
96 		if (h->magic == NULL) {
97 			err = got_error_from_errno("malloc");
98 			goto done;
99 		}
100 		n = read(p->fd, h->magic, sizeof(*h->magic));
101 		if (n < 0) {
102 			err = got_error_from_errno("read");
103 			goto done;
104 		} else if (n != sizeof(*h->magic)) {
105 			err = got_error(GOT_ERR_BAD_PACKIDX);
106 			goto done;
107 		}
108 	}
109 	if (*h->magic != htobe32(GOT_PACKIDX_V2_MAGIC)) {
110 		err = got_error(GOT_ERR_BAD_PACKIDX);
111 		goto done;
112 	}
113 	offset += sizeof(*h->magic);
114 	remain -= sizeof(*h->magic);
115 
116 	if (verify)
117 		got_hash_update(&ctx, h->magic, sizeof(*h->magic));
118 
119 	if (remain < sizeof(*h->version)) {
120 		err = got_error(GOT_ERR_BAD_PACKIDX);
121 		goto done;
122 	}
123 	if (p->map)
124 		h->version = (uint32_t *)(p->map + offset);
125 	else {
126 		h->version = malloc(sizeof(*h->version));
127 		if (h->version == NULL) {
128 			err = got_error_from_errno("malloc");
129 			goto done;
130 		}
131 		n = read(p->fd, h->version, sizeof(*h->version));
132 		if (n < 0) {
133 			err = got_error_from_errno("read");
134 			goto done;
135 		} else if (n != sizeof(*h->version)) {
136 			err = got_error(GOT_ERR_BAD_PACKIDX);
137 			goto done;
138 		}
139 	}
140 	if (*h->version != htobe32(GOT_PACKIDX_VERSION)) {
141 		err = got_error(GOT_ERR_BAD_PACKIDX);
142 		goto done;
143 	}
144 	offset += sizeof(*h->version);
145 	remain -= sizeof(*h->version);
146 
147 	if (verify)
148 		got_hash_update(&ctx, h->version, sizeof(*h->version));
149 
150 	len_fanout =
151 	    sizeof(*h->fanout_table) * GOT_PACKIDX_V2_FANOUT_TABLE_ITEMS;
152 	if (remain < len_fanout) {
153 		err = got_error(GOT_ERR_BAD_PACKIDX);
154 		goto done;
155 	}
156 	if (p->map)
157 		h->fanout_table = (uint32_t *)(p->map + offset);
158 	else {
159 		h->fanout_table = malloc(len_fanout);
160 		if (h->fanout_table == NULL) {
161 			err = got_error_from_errno("malloc");
162 			goto done;
163 		}
164 		n = read(p->fd, h->fanout_table, len_fanout);
165 		if (n < 0) {
166 			err = got_error_from_errno("read");
167 			goto done;
168 		} else if (n != len_fanout) {
169 			err = got_error(GOT_ERR_BAD_PACKIDX);
170 			goto done;
171 		}
172 	}
173 	err = verify_fanout_table(h->fanout_table);
174 	if (err)
175 		goto done;
176 	if (verify)
177 		got_hash_update(&ctx, h->fanout_table, len_fanout);
178 	offset += len_fanout;
179 	remain -= len_fanout;
180 
181 	nobj = be32toh(h->fanout_table[0xff]);
182 	len_ids = nobj * sizeof(*h->sorted_ids);
183 	if (len_ids <= nobj || len_ids > remain) {
184 		err = got_error(GOT_ERR_BAD_PACKIDX);
185 		goto done;
186 	}
187 	if (p->map)
188 		h->sorted_ids =
189 		    (struct got_packidx_object_id *)((uint8_t*)(p->map + offset));
190 	else {
191 		h->sorted_ids = malloc(len_ids);
192 		if (h->sorted_ids == NULL) {
193 			err = got_error(GOT_ERR_BAD_PACKIDX);
194 			goto done;
195 		}
196 		n = read(p->fd, h->sorted_ids, len_ids);
197 		if (n < 0)
198 			err = got_error_from_errno("read");
199 		else if (n != len_ids) {
200 			err = got_error(GOT_ERR_BAD_PACKIDX);
201 			goto done;
202 		}
203 	}
204 	if (verify)
205 		got_hash_update(&ctx, h->sorted_ids, len_ids);
206 	offset += len_ids;
207 	remain -= len_ids;
208 
209 	if (remain < nobj * sizeof(*h->crc32)) {
210 		err = got_error(GOT_ERR_BAD_PACKIDX);
211 		goto done;
212 	}
213 	if (p->map)
214 		h->crc32 = (uint32_t *)((uint8_t*)(p->map + offset));
215 	else {
216 		h->crc32 = malloc(nobj * sizeof(*h->crc32));
217 		if (h->crc32 == NULL) {
218 			err = got_error_from_errno("malloc");
219 			goto done;
220 		}
221 		n = read(p->fd, h->crc32, nobj * sizeof(*h->crc32));
222 		if (n < 0)
223 			err = got_error_from_errno("read");
224 		else if (n != nobj * sizeof(*h->crc32)) {
225 			err = got_error(GOT_ERR_BAD_PACKIDX);
226 			goto done;
227 		}
228 	}
229 	if (verify)
230 		got_hash_update(&ctx, h->crc32, nobj * sizeof(*h->crc32));
231 	remain -= nobj * sizeof(*h->crc32);
232 	offset += nobj * sizeof(*h->crc32);
233 
234 	if (remain < nobj * sizeof(*h->offsets)) {
235 		err = got_error(GOT_ERR_BAD_PACKIDX);
236 		goto done;
237 	}
238 	if (p->map)
239 		h->offsets = (uint32_t *)((uint8_t*)(p->map + offset));
240 	else {
241 		h->offsets = malloc(nobj * sizeof(*h->offsets));
242 		if (h->offsets == NULL) {
243 			err = got_error_from_errno("malloc");
244 			goto done;
245 		}
246 		n = read(p->fd, h->offsets, nobj * sizeof(*h->offsets));
247 		if (n < 0)
248 			err = got_error_from_errno("read");
249 		else if (n != nobj * sizeof(*h->offsets)) {
250 			err = got_error(GOT_ERR_BAD_PACKIDX);
251 			goto done;
252 		}
253 	}
254 	if (verify)
255 		got_hash_update(&ctx, h->offsets, nobj * sizeof(*h->offsets));
256 	remain -= nobj * sizeof(*h->offsets);
257 	offset += nobj * sizeof(*h->offsets);
258 
259 	/* Large file offsets are contained only in files > 2GB. */
260 	if (verify || packfile_size > 0x7fffffff) {
261 		for (i = 0; i < nobj; i++) {
262 			uint32_t o = h->offsets[i];
263 			if (o & htobe32(GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX))
264 				p->nlargeobj++;
265 		}
266 	}
267 	if (p->nlargeobj == 0)
268 		goto checksum;
269 	else if (packfile_size <= 0x7fffffff) {
270 		err = got_error(GOT_ERR_BAD_PACKIDX);
271 		goto done;
272 	}
273 
274 	if (remain < p->nlargeobj * sizeof(*h->large_offsets)) {
275 		err = got_error(GOT_ERR_BAD_PACKIDX);
276 		goto done;
277 	}
278 	if (p->map)
279 		h->large_offsets = (uint64_t *)((uint8_t*)(p->map + offset));
280 	else {
281 		h->large_offsets = malloc(p->nlargeobj *
282 		    sizeof(*h->large_offsets));
283 		if (h->large_offsets == NULL) {
284 			err = got_error_from_errno("malloc");
285 			goto done;
286 		}
287 		n = read(p->fd, h->large_offsets,
288 		    p->nlargeobj * sizeof(*h->large_offsets));
289 		if (n < 0)
290 			err = got_error_from_errno("read");
291 		else if (n != p->nlargeobj * sizeof(*h->large_offsets)) {
292 			err = got_error(GOT_ERR_BAD_PACKIDX);
293 			goto done;
294 		}
295 	}
296 	if (verify)
297 		got_hash_update(&ctx, h->large_offsets,
298 		    p->nlargeobj * sizeof(*h->large_offsets));
299 	remain -= p->nlargeobj * sizeof(*h->large_offsets);
300 	offset += p->nlargeobj * sizeof(*h->large_offsets);
301 
302 checksum:
303 	if (remain < sizeof(*h->trailer)) {
304 		err = got_error(GOT_ERR_BAD_PACKIDX);
305 		goto done;
306 	}
307 	if (p->map)
308 		h->trailer =
309 		    (struct got_packidx_trailer *)((uint8_t*)(p->map + offset));
310 	else {
311 		h->trailer = malloc(sizeof(*h->trailer));
312 		if (h->trailer == NULL) {
313 			err = got_error_from_errno("malloc");
314 			goto done;
315 		}
316 		n = read(p->fd, h->trailer, sizeof(*h->trailer));
317 		if (n < 0)
318 			err = got_error_from_errno("read");
319 		else if (n != sizeof(*h->trailer)) {
320 			err = got_error(GOT_ERR_BAD_PACKIDX);
321 			goto done;
322 		}
323 	}
324 	if (verify) {
325 		got_hash_update(&ctx, h->trailer->packfile_sha1,
326 		    SHA1_DIGEST_LENGTH);
327 		got_hash_final(&ctx, hash);
328 		if (got_hash_cmp(ctx.algo, hash, h->trailer->packidx_sha1)
329 		    != 0)
330 			err = got_error(GOT_ERR_PACKIDX_CSUM);
331 	}
332 done:
333 	return err;
334 }
335 
336 const struct got_error *
337 got_packidx_open(struct got_packidx **packidx,
338     int dir_fd, const char *relpath, int verify)
339 {
340 	const struct got_error *err = NULL;
341 	struct got_packidx *p = NULL;
342 	char *pack_relpath;
343 	struct stat idx_sb, pack_sb;
344 
345 	*packidx = NULL;
346 
347 	err = got_packidx_get_packfile_path(&pack_relpath, relpath);
348 	if (err)
349 		return err;
350 
351 	/*
352 	 * Ensure that a corresponding pack file exists.
353 	 * Some Git repositories have this problem. Git seems to ignore
354 	 * the existence of lonely pack index files but we do not.
355 	 */
356 	if (fstatat(dir_fd, pack_relpath, &pack_sb, 0) == -1) {
357 		if (errno == ENOENT) {
358 			err = got_error_fmt(GOT_ERR_LONELY_PACKIDX,
359 			    "%s", relpath);
360 		} else
361 			err = got_error_from_errno2("fstatat", pack_relpath);
362 		goto done;
363 	}
364 
365 	p = calloc(1, sizeof(*p));
366 	if (p == NULL) {
367 		err = got_error_from_errno("calloc");
368 		goto done;
369 	}
370 
371 	p->fd = openat(dir_fd, relpath, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
372 	if (p->fd == -1) {
373 		err = got_error_from_errno2("openat", relpath);
374 		goto done;
375 	}
376 
377 	if (fstat(p->fd, &idx_sb) != 0) {
378 		err = got_error_from_errno2("fstat", relpath);
379 		goto done;
380 	}
381 	p->len = idx_sb.st_size;
382 	if (p->len < sizeof(p->hdr)) {
383 		err = got_error(GOT_ERR_BAD_PACKIDX);
384 		goto done;
385 	}
386 
387 	p->path_packidx = strdup(relpath);
388 	if (p->path_packidx == NULL) {
389 		err = got_error_from_errno("strdup");
390 		goto done;
391 	}
392 
393 #ifndef GOT_PACK_NO_MMAP
394 	if (p->len > 0 && p->len <= SIZE_MAX) {
395 		p->map = mmap(NULL, p->len, PROT_READ, MAP_PRIVATE, p->fd, 0);
396 		if (p->map == MAP_FAILED) {
397 			if (errno != ENOMEM) {
398 				err = got_error_from_errno("mmap");
399 				goto done;
400 			}
401 			p->map = NULL; /* fall back to read(2) */
402 		}
403 	}
404 #endif
405 
406 	err = got_packidx_init_hdr(p, verify, pack_sb.st_size);
407 done:
408 	if (err) {
409 		if (p)
410 			got_packidx_close(p);
411 	} else
412 		*packidx = p;
413 	free(pack_relpath);
414 	return err;
415 }
416 
417 const struct got_error *
418 got_packidx_close(struct got_packidx *packidx)
419 {
420 	const struct got_error *err = NULL;
421 
422 	free(packidx->path_packidx);
423 	if (packidx->map) {
424 		if (munmap(packidx->map, packidx->len) == -1)
425 			err = got_error_from_errno("munmap");
426 	} else {
427 		free(packidx->hdr.magic);
428 		free(packidx->hdr.version);
429 		free(packidx->hdr.fanout_table);
430 		free(packidx->hdr.sorted_ids);
431 		free(packidx->hdr.crc32);
432 		free(packidx->hdr.offsets);
433 		free(packidx->hdr.large_offsets);
434 		free(packidx->hdr.trailer);
435 	}
436 	if (close(packidx->fd) == -1 && err == NULL)
437 		err = got_error_from_errno("close");
438 	free(packidx->sorted_offsets);
439 	free(packidx->sorted_large_offsets);
440 	free(packidx);
441 
442 	return err;
443 }
444 
445 const struct got_error *
446 got_packidx_get_packfile_path(char **path_packfile, const char *path_packidx)
447 {
448 	size_t size;
449 
450 	/* Packfile path contains ".pack" instead of ".idx", so add one byte. */
451 	size = strlen(path_packidx) + 2;
452 	if (size < GOT_PACKFILE_NAMELEN + 1)
453 		return got_error_path(path_packidx, GOT_ERR_BAD_PATH);
454 
455 	*path_packfile = malloc(size);
456 	if (*path_packfile == NULL)
457 		return got_error_from_errno("malloc");
458 
459 	/* Copy up to and excluding ".idx". */
460 	if (strlcpy(*path_packfile, path_packidx,
461 	    size - strlen(GOT_PACKIDX_SUFFIX) - 1) >= size)
462 		return got_error(GOT_ERR_NO_SPACE);
463 
464 	if (strlcat(*path_packfile, GOT_PACKFILE_SUFFIX, size) >= size)
465 		return got_error(GOT_ERR_NO_SPACE);
466 
467 	return NULL;
468 }
469 
470 off_t
471 got_packidx_get_object_offset(struct got_packidx *packidx, int idx)
472 {
473 	uint32_t offset = be32toh(packidx->hdr.offsets[idx]);
474 	if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
475 		uint64_t loffset;
476 		idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
477 		if (idx < 0 || idx >= packidx->nlargeobj ||
478 		    packidx->hdr.large_offsets == NULL)
479 			return -1;
480 		loffset = be64toh(packidx->hdr.large_offsets[idx]);
481 		return (loffset > INT64_MAX ? -1 : (off_t)loffset);
482 	}
483 	return (off_t)(offset & GOT_PACKIDX_OFFSET_VAL_MASK);
484 }
485 
486 int
487 got_packidx_get_object_idx(struct got_packidx *packidx,
488     struct got_object_id *id)
489 {
490 	u_int8_t id0 = id->sha1[0];
491 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
492 	int left = 0, right = totobj - 1;
493 
494 	if (id0 > 0)
495 		left = be32toh(packidx->hdr.fanout_table[id0 - 1]);
496 
497 	while (left <= right) {
498 		struct got_packidx_object_id *oid;
499 		int i, cmp;
500 
501 		i = ((left + right) / 2);
502 		oid = &packidx->hdr.sorted_ids[i];
503 		cmp = memcmp(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
504 		if (cmp == 0)
505 			return i;
506 		else if (cmp > 0)
507 			left = i + 1;
508 		else if (cmp < 0)
509 			right = i - 1;
510 	}
511 
512 	return -1;
513 }
514 
515 static int
516 offset_cmp(const void *pa, const void *pb)
517 {
518 	const struct got_pack_offset_index *a, *b;
519 
520 	a = (const struct got_pack_offset_index *)pa;
521 	b = (const struct got_pack_offset_index *)pb;
522 
523 	if (a->offset < b->offset)
524 		return -1;
525 	else if (a->offset > b->offset)
526 		return 1;
527 
528 	return 0;
529 }
530 
531 static int
532 large_offset_cmp(const void *pa, const void *pb)
533 {
534 	const struct got_pack_large_offset_index *a, *b;
535 
536 	a = (const struct got_pack_large_offset_index *)pa;
537 	b = (const struct got_pack_large_offset_index *)pb;
538 
539 	if (a->offset < b->offset)
540 		return -1;
541 	else if (a->offset > b->offset)
542 		return 1;
543 
544 	return 0;
545 }
546 
547 static const struct got_error *
548 build_offset_index(struct got_packidx *p)
549 {
550 	uint32_t nobj = be32toh(p->hdr.fanout_table[0xff]);
551 	unsigned int i, j, k;
552 
553 	p->sorted_offsets = calloc(nobj - p->nlargeobj,
554 	    sizeof(p->sorted_offsets[0]));
555 	if (p->sorted_offsets == NULL)
556 		return got_error_from_errno("calloc");
557 
558 	if (p->nlargeobj > 0) {
559 		p->sorted_large_offsets = calloc(p->nlargeobj,
560 		    sizeof(p->sorted_large_offsets[0]));
561 		if (p->sorted_large_offsets == NULL)
562 			return got_error_from_errno("calloc");
563 	}
564 
565 	j = 0;
566 	k = 0;
567 	for (i = 0; i < nobj; i++) {
568 		uint32_t offset = be32toh(p->hdr.offsets[i]);
569 		if (offset & GOT_PACKIDX_OFFSET_VAL_IS_LARGE_IDX) {
570 			uint64_t loffset;
571 			uint32_t idx;
572 			idx = offset & GOT_PACKIDX_OFFSET_VAL_MASK;
573 			if (idx >= p->nlargeobj ||
574 			    p->nlargeobj == 0 ||
575 			    p->hdr.large_offsets == NULL)
576 				return got_error(GOT_ERR_BAD_PACKIDX);
577 			loffset = be64toh(p->hdr.large_offsets[idx]);
578 			p->sorted_large_offsets[j].offset = loffset;
579 			p->sorted_large_offsets[j].idx = i;
580 			j++;
581 		} else {
582 			p->sorted_offsets[k].offset = offset;
583 			p->sorted_offsets[k].idx = i;
584 			k++;
585 		}
586 	}
587 	if (j != p->nlargeobj || k != nobj - p->nlargeobj)
588 		return got_error(GOT_ERR_BAD_PACKIDX);
589 
590 	qsort(p->sorted_offsets, nobj - p->nlargeobj,
591 	    sizeof(p->sorted_offsets[0]), offset_cmp);
592 
593 	if (p->sorted_large_offsets)
594 		qsort(p->sorted_large_offsets, p->nlargeobj,
595 		    sizeof(p->sorted_large_offsets[0]), large_offset_cmp);
596 
597 	return NULL;
598 }
599 
600 const struct got_error *
601 got_packidx_get_offset_idx(int *idx, struct got_packidx *packidx, off_t offset)
602 {
603 	const struct got_error *err;
604 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
605 	int i, left, right;
606 
607 	*idx = -1;
608 
609 	if (packidx->sorted_offsets == NULL) {
610 		err = build_offset_index(packidx);
611 		if (err)
612 			return err;
613 	}
614 
615 	if (offset >= 0x7fffffff) {
616 		uint64_t lo;
617 		left = 0, right = packidx->nlargeobj - 1;
618 		while (left <= right) {
619 			i = ((left + right) / 2);
620 			lo = packidx->sorted_large_offsets[i].offset;
621 			if (lo == offset) {
622 				*idx = packidx->sorted_large_offsets[i].idx;
623 				break;
624 			} else if (offset > lo)
625 				left = i + 1;
626 			else if (offset < lo)
627 				right = i - 1;
628 		}
629 	} else {
630 		uint32_t o;
631 		left = 0, right = totobj - packidx->nlargeobj - 1;
632 		while (left <= right) {
633 			i = ((left + right) / 2);
634 			o = packidx->sorted_offsets[i].offset;
635 			if (o == offset) {
636 				*idx = packidx->sorted_offsets[i].idx;
637 				break;
638 			} else if (offset > o)
639 				left = i + 1;
640 			else if (offset < o)
641 				right = i - 1;
642 		}
643 	}
644 
645 	return NULL;
646 }
647 
648 const struct got_error *
649 got_packidx_get_object_id(struct got_object_id *id,
650     struct got_packidx *packidx, int idx)
651 {
652 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
653 	struct got_packidx_object_id *oid;
654 
655 	if (idx < 0 || idx >= totobj)
656 		return got_error(GOT_ERR_NO_OBJ);
657 
658 	oid = &packidx->hdr.sorted_ids[idx];
659 	memcpy(id->sha1, oid->sha1, SHA1_DIGEST_LENGTH);
660 	return NULL;
661 }
662 
663 const struct got_error *
664 got_packidx_match_id_str_prefix(struct got_object_id_queue *matched_ids,
665     struct got_packidx *packidx, const char *id_str_prefix)
666 {
667 	const struct got_error *err = NULL;
668 	u_int8_t id0;
669 	uint32_t totobj = be32toh(packidx->hdr.fanout_table[0xff]);
670 	char hex[3];
671 	size_t prefix_len = strlen(id_str_prefix);
672 	struct got_packidx_object_id *oid;
673 	uint32_t i = 0;
674 
675 	STAILQ_INIT(matched_ids);
676 
677 	if (prefix_len < 2)
678 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
679 
680 	hex[0] = id_str_prefix[0];
681 	hex[1] = id_str_prefix[1];
682 	hex[2] = '\0';
683 	if (!got_parse_xdigit(&id0, hex))
684 		return got_error_path(id_str_prefix, GOT_ERR_BAD_OBJ_ID_STR);
685 
686 	if (id0 > 0)
687 		i = be32toh(packidx->hdr.fanout_table[id0 - 1]);
688 	oid = &packidx->hdr.sorted_ids[i];
689 	while (i < totobj && oid->sha1[0] == id0) {
690 		char id_str[SHA1_DIGEST_STRING_LENGTH];
691 		struct got_object_qid *qid;
692 		int cmp;
693 
694 		if (!got_sha1_digest_to_str(oid->sha1, id_str, sizeof(id_str)))
695 		        return got_error(GOT_ERR_NO_SPACE);
696 
697 		cmp = strncmp(id_str, id_str_prefix, prefix_len);
698 		if (cmp < 0) {
699 			oid = &packidx->hdr.sorted_ids[++i];
700 			continue;
701 		} else if (cmp > 0)
702 			break;
703 
704 		err = got_object_qid_alloc_partial(&qid);
705 		if (err)
706 			break;
707 		memcpy(qid->id.sha1, oid->sha1, SHA1_DIGEST_LENGTH);
708 		STAILQ_INSERT_TAIL(matched_ids, qid, entry);
709 
710 		oid = &packidx->hdr.sorted_ids[++i];
711 	}
712 
713 	if (err)
714 		got_object_id_queue_free(matched_ids);
715 	return err;
716 }
717 
718 static void
719 set_max_datasize(void)
720 {
721 	struct rlimit rl;
722 
723 	if (getrlimit(RLIMIT_DATA, &rl) != 0)
724 		return;
725 
726 	rl.rlim_cur = rl.rlim_max;
727 	setrlimit(RLIMIT_DATA, &rl);
728 }
729 
730 const struct got_error *
731 got_pack_start_privsep_child(struct got_pack *pack, struct got_packidx *packidx)
732 {
733 	const struct got_error *err = NULL;
734 	int imsg_fds[2];
735 	pid_t pid;
736 	struct imsgbuf *ibuf;
737 
738 	ibuf = calloc(1, sizeof(*ibuf));
739 	if (ibuf == NULL)
740 		return got_error_from_errno("calloc");
741 
742 	pack->privsep_child = calloc(1, sizeof(*pack->privsep_child));
743 	if (pack->privsep_child == NULL) {
744 		err = got_error_from_errno("calloc");
745 		free(ibuf);
746 		return err;
747 	}
748 	pack->child_has_tempfiles = 0;
749 	pack->child_has_delta_outfd = 0;
750 
751 	if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, imsg_fds) == -1) {
752 		err = got_error_from_errno("socketpair");
753 		goto done;
754 	}
755 
756 	pid = fork();
757 	if (pid == -1) {
758 		err = got_error_from_errno("fork");
759 		goto done;
760 	} else if (pid == 0) {
761 		set_max_datasize();
762 		got_privsep_exec_child(imsg_fds, GOT_PATH_PROG_READ_PACK,
763 		    pack->path_packfile);
764 		/* not reached */
765 	}
766 
767 	if (close(imsg_fds[1]) == -1)
768 		return got_error_from_errno("close");
769 	pack->privsep_child->imsg_fd = imsg_fds[0];
770 	pack->privsep_child->pid = pid;
771 	imsg_init(ibuf, imsg_fds[0]);
772 	pack->privsep_child->ibuf = ibuf;
773 
774 	err = got_privsep_init_pack_child(ibuf, pack, packidx);
775 	if (err) {
776 		const struct got_error *child_err;
777 		err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
778 		child_err = got_privsep_wait_for_child(
779 		    pack->privsep_child->pid);
780 		if (child_err && err == NULL)
781 			err = child_err;
782 	}
783 done:
784 	if (err) {
785 		free(ibuf);
786 		free(pack->privsep_child);
787 		pack->privsep_child = NULL;
788 	}
789 	return err;
790 }
791 
792 static const struct got_error *
793 pack_stop_privsep_child(struct got_pack *pack)
794 {
795 	const struct got_error *err = NULL, *close_err = NULL;
796 
797 	if (pack->privsep_child == NULL)
798 		return NULL;
799 
800 	err = got_privsep_send_stop(pack->privsep_child->imsg_fd);
801 	if (err)
802 		return err;
803 	if (close(pack->privsep_child->imsg_fd) == -1)
804 		close_err = got_error_from_errno("close");
805 	err = got_privsep_wait_for_child(pack->privsep_child->pid);
806 	if (close_err && err == NULL)
807 		err = close_err;
808 	imsg_clear(pack->privsep_child->ibuf);
809 	free(pack->privsep_child->ibuf);
810 	free(pack->privsep_child);
811 	pack->privsep_child = NULL;
812 	return err;
813 }
814 
815 const struct got_error *
816 got_pack_close(struct got_pack *pack)
817 {
818 	const struct got_error *err = NULL;
819 
820 	err = pack_stop_privsep_child(pack);
821 	if (pack->map && munmap(pack->map, pack->filesize) == -1 && !err)
822 		err = got_error_from_errno("munmap");
823 	if (pack->fd != -1 && close(pack->fd) == -1 && err == NULL)
824 		err = got_error_from_errno("close");
825 	pack->fd = -1;
826 	free(pack->path_packfile);
827 	pack->path_packfile = NULL;
828 	pack->filesize = 0;
829 	if (pack->delta_cache) {
830 		got_delta_cache_free(pack->delta_cache);
831 		pack->delta_cache = NULL;
832 	}
833 
834 	/*
835 	 * Leave accumfd and basefd alone. They are managed by the
836 	 * repository layer and can be reused.
837 	 */
838 
839 	return err;
840 }
841 
842 const struct got_error *
843 got_pack_parse_object_type_and_size(uint8_t *type, uint64_t *size, size_t *len,
844     struct got_pack *pack, off_t offset)
845 {
846 	uint8_t t = 0;
847 	uint64_t s = 0;
848 	uint8_t sizeN;
849 	size_t mapoff = 0;
850 	int i = 0;
851 
852 	*len = 0;
853 
854 	if (offset >= pack->filesize)
855 		return got_error(GOT_ERR_PACK_OFFSET);
856 
857 	if (pack->map) {
858 		if (offset > SIZE_MAX) {
859 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
860 			    "offset %lld overflows size_t",
861 			    (long long)offset);
862 		}
863 
864 		mapoff = (size_t)offset;
865 	} else {
866 		if (lseek(pack->fd, offset, SEEK_SET) == -1)
867 			return got_error_from_errno("lseek");
868 	}
869 
870 	do {
871 		/* We do not support size values which don't fit in 64 bit. */
872 		if (i > 9)
873 			return got_error_fmt(GOT_ERR_OBJ_TOO_LARGE,
874 			    "packfile offset %lld", (long long)offset);
875 
876 		if (pack->map) {
877 			if (mapoff + sizeof(sizeN) >= pack->filesize)
878 				return got_error(GOT_ERR_BAD_PACKFILE);
879 			sizeN = *(pack->map + mapoff);
880 			mapoff += sizeof(sizeN);
881 		} else {
882 			ssize_t n = read(pack->fd, &sizeN, sizeof(sizeN));
883 			if (n < 0)
884 				return got_error_from_errno("read");
885 			if (n != sizeof(sizeN))
886 				return got_error(GOT_ERR_BAD_PACKFILE);
887 		}
888 		*len += sizeof(sizeN);
889 
890 		if (i == 0) {
891 			t = (sizeN & GOT_PACK_OBJ_SIZE0_TYPE_MASK) >>
892 			    GOT_PACK_OBJ_SIZE0_TYPE_MASK_SHIFT;
893 			s = (sizeN & GOT_PACK_OBJ_SIZE0_VAL_MASK);
894 		} else {
895 			size_t shift = 4 + 7 * (i - 1);
896 			s |= ((sizeN & GOT_PACK_OBJ_SIZE_VAL_MASK) << shift);
897 		}
898 		i++;
899 	} while (sizeN & GOT_PACK_OBJ_SIZE_MORE);
900 
901 	*type = t;
902 	*size = s;
903 	return NULL;
904 }
905 
906 static const struct got_error *
907 open_plain_object(struct got_object **obj, struct got_object_id *id,
908     uint8_t type, off_t offset, size_t size, int idx)
909 {
910 	*obj = calloc(1, sizeof(**obj));
911 	if (*obj == NULL)
912 		return got_error_from_errno("calloc");
913 
914 	(*obj)->type = type;
915 	(*obj)->flags = GOT_OBJ_FLAG_PACKED;
916 	(*obj)->pack_idx = idx;
917 	(*obj)->hdrlen = 0;
918 	(*obj)->size = size;
919 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
920 	(*obj)->pack_offset = offset;
921 
922 	return NULL;
923 }
924 
925 static const struct got_error *
926 parse_negative_offset(int64_t *offset, size_t *len, struct got_pack *pack,
927     off_t delta_offset)
928 {
929 	int64_t o = 0;
930 	uint8_t offN;
931 	int i = 0;
932 
933 	*offset = 0;
934 	*len = 0;
935 
936 	do {
937 		/* We do not support offset values which don't fit in 64 bit. */
938 		if (i > 8)
939 			return got_error(GOT_ERR_NO_SPACE);
940 
941 		if (pack->map) {
942 			size_t mapoff;
943 
944 			if (delta_offset + *len > SIZE_MAX) {
945 				return got_error_fmt(GOT_ERR_PACK_OFFSET,
946 				    "mapoff %lld would overflow size_t",
947 				    (long long)delta_offset + *len);
948 			}
949 
950 			mapoff = (size_t)delta_offset + *len;
951 			if (mapoff + sizeof(offN) >= pack->filesize)
952 				return got_error(GOT_ERR_PACK_OFFSET);
953 			offN = *(pack->map + mapoff);
954 		} else {
955 			ssize_t n;
956 			n = read(pack->fd, &offN, sizeof(offN));
957 			if (n < 0)
958 				return got_error_from_errno("read");
959 			if (n != sizeof(offN))
960 				return got_error(GOT_ERR_BAD_PACKFILE);
961 		}
962 		*len += sizeof(offN);
963 
964 		if (i == 0)
965 			o = (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
966 		else {
967 			o++;
968 			o <<= 7;
969 			o += (offN & GOT_PACK_OBJ_DELTA_OFF_VAL_MASK);
970 		}
971 		i++;
972 	} while (offN & GOT_PACK_OBJ_DELTA_OFF_MORE);
973 
974 	*offset = o;
975 	return NULL;
976 }
977 
978 const struct got_error *
979 got_pack_parse_offset_delta(off_t *base_offset, size_t *len,
980     struct got_pack *pack, off_t offset, size_t tslen)
981 {
982 	const struct got_error *err;
983 	int64_t negoffset;
984 	size_t negofflen;
985 
986 	*len = 0;
987 
988 	err = parse_negative_offset(&negoffset, &negofflen, pack,
989 	    offset + tslen);
990 	if (err)
991 		return err;
992 
993 	/* Compute the base object's offset (must be in the same pack file). */
994 	*base_offset = (offset - negoffset);
995 	if (*base_offset <= 0)
996 		return got_error(GOT_ERR_BAD_PACKFILE);
997 
998 	*len = negofflen;
999 	return NULL;
1000 }
1001 
1002 static const struct got_error *
1003 read_delta_data(uint8_t **delta_buf, size_t *delta_len,
1004     size_t *delta_compressed_len, size_t delta_data_offset,
1005     struct got_pack *pack)
1006 {
1007 	const struct got_error *err = NULL;
1008 	size_t consumed = 0;
1009 
1010 	if (pack->map) {
1011 		if (delta_data_offset >= pack->filesize)
1012 			return got_error(GOT_ERR_PACK_OFFSET);
1013 		err = got_inflate_to_mem_mmap(delta_buf, delta_len,
1014 		    &consumed, NULL, pack->map, delta_data_offset,
1015 		    pack->filesize - delta_data_offset);
1016 		if (err)
1017 			return err;
1018 	} else {
1019 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1)
1020 			return got_error_from_errno("lseek");
1021 		err = got_inflate_to_mem_fd(delta_buf, delta_len,
1022 		    &consumed, NULL, 0, pack->fd);
1023 		if (err)
1024 			return err;
1025 	}
1026 
1027 	if (delta_compressed_len)
1028 		*delta_compressed_len = consumed;
1029 
1030 	return NULL;
1031 }
1032 
1033 static const struct got_error *
1034 add_delta(struct got_delta_chain *deltas, off_t delta_offset, size_t tslen,
1035     int delta_type, size_t delta_size, off_t delta_data_offset)
1036 {
1037 	struct got_delta *delta;
1038 
1039 	delta = got_delta_open(delta_offset, tslen, delta_type, delta_size,
1040 	    delta_data_offset);
1041 	if (delta == NULL)
1042 		return got_error_from_errno("got_delta_open");
1043 	/* delta is freed in got_object_close() */
1044 	deltas->nentries++;
1045 	STAILQ_INSERT_HEAD(&deltas->entries, delta, entry);
1046 	return NULL;
1047 }
1048 
1049 static const struct got_error *
1050 resolve_offset_delta(struct got_delta_chain *deltas,
1051     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1052     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1053 {
1054 	const struct got_error *err;
1055 	off_t base_offset;
1056 	uint8_t base_type;
1057 	uint64_t base_size;
1058 	size_t base_tslen;
1059 	off_t delta_data_offset;
1060 	size_t consumed;
1061 
1062 	err = got_pack_parse_offset_delta(&base_offset, &consumed, pack,
1063 	    delta_offset, tslen);
1064 	if (err)
1065 		return err;
1066 
1067 	delta_data_offset = delta_offset + tslen + consumed;
1068 	if (delta_data_offset >= pack->filesize)
1069 		return got_error(GOT_ERR_PACK_OFFSET);
1070 
1071 	if (pack->map == NULL) {
1072 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1073 		if (delta_data_offset == -1)
1074 			return got_error_from_errno("lseek");
1075 	}
1076 
1077 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1078 	    delta_data_offset);
1079 	if (err)
1080 		return err;
1081 
1082 	/* An offset delta must be in the same packfile. */
1083 	if (base_offset >= pack->filesize)
1084 		return got_error(GOT_ERR_PACK_OFFSET);
1085 
1086 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1087 	    &base_tslen, pack, base_offset);
1088 	if (err)
1089 		return err;
1090 
1091 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1092 	    base_tslen, base_type, base_size, recursion - 1);
1093 }
1094 
1095 const struct got_error *
1096 got_pack_parse_ref_delta(struct got_object_id *id,
1097     struct got_pack *pack, off_t delta_offset, int tslen)
1098 {
1099 	if (pack->map) {
1100 		size_t mapoff;
1101 
1102 		if (delta_offset + tslen > SIZE_MAX) {
1103 			return got_error_fmt(GOT_ERR_PACK_OFFSET,
1104 			    "mapoff %lld would overflow size_t",
1105 			    (long long)delta_offset + tslen);
1106 		}
1107 
1108 		mapoff = delta_offset + tslen;
1109 		if (mapoff + sizeof(*id) >= pack->filesize)
1110 			return got_error(GOT_ERR_PACK_OFFSET);
1111 		memcpy(id, pack->map + mapoff, sizeof(*id));
1112 	} else {
1113 		ssize_t n;
1114 		n = read(pack->fd, id, sizeof(*id));
1115 		if (n < 0)
1116 			return got_error_from_errno("read");
1117 		if (n != sizeof(*id))
1118 			return got_error(GOT_ERR_BAD_PACKFILE);
1119 	}
1120 
1121 	return NULL;
1122 }
1123 
1124 static const struct got_error *
1125 resolve_ref_delta(struct got_delta_chain *deltas, struct got_packidx *packidx,
1126     struct got_pack *pack, off_t delta_offset, size_t tslen, int delta_type,
1127     size_t delta_size, unsigned int recursion)
1128 {
1129 	const struct got_error *err;
1130 	struct got_object_id id;
1131 	int idx;
1132 	off_t base_offset;
1133 	uint8_t base_type;
1134 	uint64_t base_size;
1135 	size_t base_tslen;
1136 	off_t delta_data_offset;
1137 
1138 	if (delta_offset + tslen >= pack->filesize)
1139 		return got_error(GOT_ERR_PACK_OFFSET);
1140 
1141 	err = got_pack_parse_ref_delta(&id, pack, delta_offset, tslen);
1142 	if (err)
1143 		return err;
1144 	if (pack->map) {
1145 		delta_data_offset = delta_offset + tslen + SHA1_DIGEST_LENGTH;
1146 	} else {
1147 		delta_data_offset = lseek(pack->fd, 0, SEEK_CUR);
1148 		if (delta_data_offset == -1)
1149 			return got_error_from_errno("lseek");
1150 	}
1151 
1152 	err = add_delta(deltas, delta_offset, tslen, delta_type, delta_size,
1153 	    delta_data_offset);
1154 	if (err)
1155 		return err;
1156 
1157 	/* Delta base must be in the same pack file. */
1158 	idx = got_packidx_get_object_idx(packidx, &id);
1159 	if (idx == -1)
1160 		return got_error(GOT_ERR_NO_OBJ);
1161 
1162 	base_offset = got_packidx_get_object_offset(packidx, idx);
1163 	if (base_offset == -1)
1164 		return got_error(GOT_ERR_BAD_PACKIDX);
1165 
1166 	if (base_offset >= pack->filesize)
1167 		return got_error(GOT_ERR_PACK_OFFSET);
1168 
1169 	err = got_pack_parse_object_type_and_size(&base_type, &base_size,
1170 	    &base_tslen, pack, base_offset);
1171 	if (err)
1172 		return err;
1173 
1174 	return got_pack_resolve_delta_chain(deltas, packidx, pack, base_offset,
1175 	    base_tslen, base_type, base_size, recursion - 1);
1176 }
1177 
1178 const struct got_error *
1179 got_pack_resolve_delta_chain(struct got_delta_chain *deltas,
1180     struct got_packidx *packidx, struct got_pack *pack, off_t delta_offset,
1181     size_t tslen, int delta_type, size_t delta_size, unsigned int recursion)
1182 {
1183 	const struct got_error *err = NULL;
1184 
1185 	if (--recursion == 0)
1186 		return got_error(GOT_ERR_RECURSION);
1187 
1188 	switch (delta_type) {
1189 	case GOT_OBJ_TYPE_COMMIT:
1190 	case GOT_OBJ_TYPE_TREE:
1191 	case GOT_OBJ_TYPE_BLOB:
1192 	case GOT_OBJ_TYPE_TAG:
1193 		/* Plain types are the final delta base. Recursion ends. */
1194 		err = add_delta(deltas, delta_offset, tslen, delta_type,
1195 		    delta_size, 0);
1196 		break;
1197 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1198 		err = resolve_offset_delta(deltas, packidx, pack,
1199 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1200 		break;
1201 	case GOT_OBJ_TYPE_REF_DELTA:
1202 		err = resolve_ref_delta(deltas, packidx, pack,
1203 		    delta_offset, tslen, delta_type, delta_size, recursion - 1);
1204 		break;
1205 	default:
1206 		return got_error(GOT_ERR_OBJ_TYPE);
1207 	}
1208 
1209 	return err;
1210 }
1211 
1212 static const struct got_error *
1213 open_delta_object(struct got_object **obj, struct got_packidx *packidx,
1214     struct got_pack *pack, struct got_object_id *id, off_t offset,
1215     size_t tslen, int delta_type, size_t delta_size, int idx)
1216 {
1217 	const struct got_error *err = NULL;
1218 	int resolved_type;
1219 
1220 	*obj = calloc(1, sizeof(**obj));
1221 	if (*obj == NULL)
1222 		return got_error_from_errno("calloc");
1223 
1224 	(*obj)->flags = 0;
1225 	(*obj)->hdrlen = 0;
1226 	(*obj)->size = 0; /* Not known because deltas aren't applied yet. */
1227 	memcpy(&(*obj)->id, id, sizeof((*obj)->id));
1228 	(*obj)->pack_offset = offset + tslen;
1229 
1230 	STAILQ_INIT(&(*obj)->deltas.entries);
1231 	(*obj)->flags |= GOT_OBJ_FLAG_DELTIFIED;
1232 	(*obj)->flags |= GOT_OBJ_FLAG_PACKED;
1233 	(*obj)->pack_idx = idx;
1234 
1235 	err = got_pack_resolve_delta_chain(&(*obj)->deltas, packidx, pack,
1236 	    offset, tslen, delta_type, delta_size,
1237 	    GOT_DELTA_CHAIN_RECURSION_MAX);
1238 	if (err)
1239 		goto done;
1240 
1241 	err = got_delta_chain_get_base_type(&resolved_type, &(*obj)->deltas);
1242 	if (err)
1243 		goto done;
1244 	(*obj)->type = resolved_type;
1245 done:
1246 	if (err) {
1247 		got_object_close(*obj);
1248 		*obj = NULL;
1249 	}
1250 	return err;
1251 }
1252 
1253 const struct got_error *
1254 got_packfile_open_object(struct got_object **obj, struct got_pack *pack,
1255     struct got_packidx *packidx, int idx, struct got_object_id *id)
1256 {
1257 	const struct got_error *err = NULL;
1258 	off_t offset;
1259 	uint8_t type;
1260 	uint64_t size;
1261 	size_t tslen;
1262 
1263 	*obj = NULL;
1264 
1265 	offset = got_packidx_get_object_offset(packidx, idx);
1266 	if (offset == -1)
1267 		return got_error(GOT_ERR_BAD_PACKIDX);
1268 
1269 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1270 	    pack, offset);
1271 	if (err)
1272 		return err;
1273 
1274 	switch (type) {
1275 	case GOT_OBJ_TYPE_COMMIT:
1276 	case GOT_OBJ_TYPE_TREE:
1277 	case GOT_OBJ_TYPE_BLOB:
1278 	case GOT_OBJ_TYPE_TAG:
1279 		err = open_plain_object(obj, id, type, offset + tslen,
1280 		    size, idx);
1281 		break;
1282 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1283 	case GOT_OBJ_TYPE_REF_DELTA:
1284 		err = open_delta_object(obj, packidx, pack, id, offset,
1285 		    tslen, type, size, idx);
1286 		break;
1287 	default:
1288 		err = got_error(GOT_ERR_OBJ_TYPE);
1289 		break;
1290 	}
1291 
1292 	return err;
1293 }
1294 
1295 const struct got_error *
1296 got_pack_get_delta_chain_max_size(uint64_t *max_size,
1297     struct got_delta_chain *deltas, struct got_pack *pack)
1298 {
1299 	struct got_delta *delta;
1300 	uint64_t base_size = 0, result_size = 0;
1301 
1302 	*max_size = 0;
1303 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1304 		/* Plain object types are the delta base. */
1305 		if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1306 		    delta->type != GOT_OBJ_TYPE_TREE &&
1307 		    delta->type != GOT_OBJ_TYPE_BLOB &&
1308 		    delta->type != GOT_OBJ_TYPE_TAG) {
1309 			const struct got_error *err;
1310 			uint8_t *delta_buf = NULL;
1311 			size_t delta_len;
1312 			int cached = 1;
1313 
1314 			if (pack->delta_cache) {
1315 				got_delta_cache_get(&delta_buf, &delta_len,
1316 				    pack->delta_cache, delta->data_offset);
1317 			}
1318 			if (delta_buf == NULL) {
1319 				cached = 0;
1320 				err = read_delta_data(&delta_buf, &delta_len,
1321 				    NULL, delta->data_offset, pack);
1322 				if (err)
1323 					return err;
1324 			}
1325 			if (pack->delta_cache && !cached) {
1326 				err = got_delta_cache_add(pack->delta_cache,
1327 				    delta->data_offset, delta_buf, delta_len);
1328 				if (err == NULL)
1329 					cached = 1;
1330 				else if (err->code != GOT_ERR_NO_SPACE) {
1331 					free(delta_buf);
1332 					return err;
1333 				}
1334 			}
1335 			err = got_delta_get_sizes(&base_size, &result_size,
1336 			    delta_buf, delta_len);
1337 			if (!cached)
1338 				free(delta_buf);
1339 			if (err)
1340 				return err;
1341 		} else
1342 			base_size = delta->size;
1343 		if (base_size > *max_size)
1344 			*max_size = base_size;
1345 		if (result_size > *max_size)
1346 			*max_size = result_size;
1347 	}
1348 
1349 	return NULL;
1350 }
1351 
1352 const struct got_error *
1353 got_pack_get_max_delta_object_size(uint64_t *size, struct got_object *obj,
1354     struct got_pack *pack)
1355 {
1356 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0)
1357 		return got_error(GOT_ERR_OBJ_TYPE);
1358 
1359 	return got_pack_get_delta_chain_max_size(size, &obj->deltas, pack);
1360 }
1361 
1362 const struct got_error *
1363 got_pack_dump_delta_chain_to_file(size_t *result_size,
1364     struct got_delta_chain *deltas, struct got_pack *pack, FILE *outfile,
1365     FILE *base_file, FILE *accum_file)
1366 {
1367 	const struct got_error *err = NULL;
1368 	struct got_delta *delta;
1369 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1370 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1371 	/* We process small enough files entirely in memory for speed. */
1372 	const size_t max_bufsize = GOT_DELTA_RESULT_SIZE_CACHED_MAX;
1373 	uint64_t max_size = 0;
1374 	int n = 0;
1375 
1376 	*result_size = 0;
1377 
1378 	if (STAILQ_EMPTY(&deltas->entries))
1379 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1380 
1381 	if (fseeko(base_file, 0L, SEEK_SET) == -1)
1382 		return got_error_from_errno("fseeko");
1383 	if (fseeko(accum_file, 0L, SEEK_SET) == -1)
1384 		return got_error_from_errno("fseeko");
1385 
1386 	/* Deltas are ordered in ascending order. */
1387 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1388 		uint8_t *delta_buf = NULL;
1389 		uint64_t base_size, result_size = 0;
1390 		int cached = 1;
1391 		if (n == 0) {
1392 			size_t mapoff;
1393 			off_t delta_data_offset;
1394 
1395 			/* Plain object types are the delta base. */
1396 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1397 			    delta->type != GOT_OBJ_TYPE_TREE &&
1398 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1399 			    delta->type != GOT_OBJ_TYPE_TAG) {
1400 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1401 				goto done;
1402 			}
1403 
1404 			delta_data_offset = delta->offset + delta->tslen;
1405 			if (delta_data_offset >= pack->filesize) {
1406 				err = got_error(GOT_ERR_PACK_OFFSET);
1407 				goto done;
1408 			}
1409 			if (pack->map == NULL) {
1410 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1411 				    == -1) {
1412 					err = got_error_from_errno("lseek");
1413 					goto done;
1414 				}
1415 			}
1416 			if (delta->size > max_size)
1417 				max_size = delta->size;
1418 			if (max_size > max_bufsize) {
1419 				if (pack->map) {
1420 					if (delta_data_offset > SIZE_MAX) {
1421 						return got_error_fmt(
1422 						    GOT_ERR_RANGE,
1423 						    "delta offset %lld "
1424 						    "overflows size_t",
1425 						    (long long)
1426 						    delta_data_offset);
1427 					}
1428 
1429 					mapoff = delta_data_offset;
1430 					err = got_inflate_to_file_mmap(
1431 					    &base_bufsz, NULL, NULL, pack->map,
1432 					    mapoff, pack->filesize - mapoff,
1433 					    base_file);
1434 				} else
1435 					err = got_inflate_to_file_fd(
1436 					    &base_bufsz, NULL, NULL, pack->fd,
1437 					    base_file);
1438 			} else {
1439 				accum_buf = malloc(max_size);
1440 				if (accum_buf == NULL) {
1441 					err = got_error_from_errno("malloc");
1442 					goto done;
1443 				}
1444 				accum_bufsz = max_size;
1445 				if (pack->map) {
1446 					if (delta_data_offset > SIZE_MAX) {
1447 						return got_error_fmt(
1448 						    GOT_ERR_RANGE,
1449 						    "delta offset %lld "
1450 						    "overflows size_t",
1451 						    (long long)
1452 						    delta_data_offset);
1453 					}
1454 
1455 					mapoff = delta_data_offset;
1456 					err = got_inflate_to_mem_mmap(&base_buf,
1457 					    &base_bufsz, NULL, NULL,
1458 					    pack->map, mapoff,
1459 					    pack->filesize - mapoff);
1460 				} else
1461 					err = got_inflate_to_mem_fd(&base_buf,
1462 					    &base_bufsz, NULL, NULL, max_size,
1463 					    pack->fd);
1464 			}
1465 			if (err)
1466 				goto done;
1467 			n++;
1468 			if (base_buf == NULL)
1469 				rewind(base_file);
1470 			continue;
1471 		}
1472 
1473 		if (pack->delta_cache) {
1474 			got_delta_cache_get(&delta_buf, &delta_len,
1475 			    pack->delta_cache, delta->data_offset);
1476 		}
1477 		if (delta_buf == NULL) {
1478 			cached = 0;
1479 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1480 			    delta->data_offset, pack);
1481 			if (err)
1482 				goto done;
1483 		}
1484 		if (pack->delta_cache && !cached) {
1485 			err = got_delta_cache_add(pack->delta_cache,
1486 			    delta->data_offset, delta_buf, delta_len);
1487 			if (err == NULL)
1488 				cached = 1;
1489 			else if (err->code != GOT_ERR_NO_SPACE) {
1490 				free(delta_buf);
1491 				goto done;
1492 			}
1493 		}
1494 
1495 		err = got_delta_get_sizes(&base_size, &result_size,
1496 		    delta_buf, delta_len);
1497 		if (err) {
1498 			if (!cached)
1499 				free(delta_buf);
1500 			goto done;
1501 		}
1502 		if (base_size > max_size)
1503 			max_size = base_size;
1504 		if (result_size > max_size)
1505 			max_size = result_size;
1506 
1507 		if (base_buf && max_size > max_bufsize) {
1508 			/* Switch from buffers to temporary files. */
1509 			size_t w = fwrite(base_buf, 1, base_bufsz,
1510 			    base_file);
1511 			if (w != base_bufsz) {
1512 				err = got_ferror(outfile, GOT_ERR_IO);
1513 				if (!cached)
1514 					free(delta_buf);
1515 				goto done;
1516 			}
1517 			free(base_buf);
1518 			base_buf = NULL;
1519 			free(accum_buf);
1520 			accum_buf = NULL;
1521 		}
1522 
1523 		if (base_buf && max_size > base_bufsz) {
1524 			uint8_t *p = realloc(base_buf, max_size);
1525 			if (p == NULL) {
1526 				err = got_error_from_errno("realloc");
1527 				if (!cached)
1528 					free(delta_buf);
1529 				goto done;
1530 			}
1531 			base_buf = p;
1532 			base_bufsz = max_size;
1533 		}
1534 
1535 		if (accum_buf && max_size > accum_bufsz) {
1536 			uint8_t *p = realloc(accum_buf, max_size);
1537 			if (p == NULL) {
1538 				err = got_error_from_errno("realloc");
1539 				if (!cached)
1540 					free(delta_buf);
1541 				goto done;
1542 			}
1543 			accum_buf = p;
1544 			accum_bufsz = max_size;
1545 		}
1546 
1547 		if (base_buf) {
1548 			err = got_delta_apply_in_mem(base_buf, base_bufsz,
1549 			    delta_buf, delta_len, accum_buf,
1550 			    &accum_size, max_size);
1551 			n++;
1552 		} else {
1553 			err = got_delta_apply(base_file, delta_buf,
1554 			    delta_len,
1555 			    /* Final delta application writes to output file. */
1556 			    ++n < deltas->nentries ? accum_file : outfile,
1557 			    &accum_size);
1558 		}
1559 		if (!cached)
1560 			free(delta_buf);
1561 		if (err)
1562 			goto done;
1563 
1564 		if (n < deltas->nentries) {
1565 			/* Accumulated delta becomes the new base. */
1566 			if (base_buf) {
1567 				uint8_t *tmp = accum_buf;
1568 				size_t tmp_size = accum_bufsz;
1569 				accum_buf = base_buf;
1570 				accum_bufsz = base_bufsz;
1571 				base_buf = tmp;
1572 				base_bufsz = tmp_size;
1573 			} else {
1574 				FILE *tmp = accum_file;
1575 				accum_file = base_file;
1576 				base_file = tmp;
1577 				rewind(base_file);
1578 				rewind(accum_file);
1579 			}
1580 		}
1581 	}
1582 
1583 done:
1584 	free(base_buf);
1585 	if (accum_buf) {
1586 		size_t len = fwrite(accum_buf, 1, accum_size, outfile);
1587 		free(accum_buf);
1588 		if (len != accum_size)
1589 			err = got_ferror(outfile, GOT_ERR_IO);
1590 	}
1591 	rewind(outfile);
1592 	if (err == NULL)
1593 		*result_size = accum_size;
1594 	return err;
1595 }
1596 
1597 const struct got_error *
1598 got_pack_dump_delta_chain_to_mem(uint8_t **outbuf, size_t *outlen,
1599     struct got_delta_chain *deltas, struct got_pack *pack)
1600 {
1601 	const struct got_error *err = NULL;
1602 	struct got_delta *delta;
1603 	uint8_t *base_buf = NULL, *accum_buf = NULL;
1604 	size_t base_bufsz = 0, accum_bufsz = 0, accum_size = 0, delta_len;
1605 	uint64_t max_size = 0;
1606 	int n = 0;
1607 
1608 	*outbuf = NULL;
1609 	*outlen = 0;
1610 
1611 	if (STAILQ_EMPTY(&deltas->entries))
1612 		return got_error(GOT_ERR_BAD_DELTA_CHAIN);
1613 
1614 	/* Deltas are ordered in ascending order. */
1615 	STAILQ_FOREACH(delta, &deltas->entries, entry) {
1616 		uint8_t *delta_buf = NULL;
1617 		uint64_t base_size, result_size = 0;
1618 		int cached = 1;
1619 		if (n == 0) {
1620 			off_t delta_data_offset;
1621 
1622 			/* Plain object types are the delta base. */
1623 			if (delta->type != GOT_OBJ_TYPE_COMMIT &&
1624 			    delta->type != GOT_OBJ_TYPE_TREE &&
1625 			    delta->type != GOT_OBJ_TYPE_BLOB &&
1626 			    delta->type != GOT_OBJ_TYPE_TAG) {
1627 				err = got_error(GOT_ERR_BAD_DELTA_CHAIN);
1628 				goto done;
1629 			}
1630 
1631 			delta_data_offset = delta->offset + delta->tslen;
1632 			if (delta_data_offset >= pack->filesize) {
1633 				err = got_error(GOT_ERR_PACK_OFFSET);
1634 				goto done;
1635 			}
1636 
1637 			if (delta->size > max_size)
1638 				max_size = delta->size;
1639 
1640 			if (pack->map) {
1641 				size_t mapoff;
1642 
1643 				if (delta_data_offset > SIZE_MAX) {
1644 					return got_error_fmt(GOT_ERR_RANGE,
1645 					    "delta %lld offset would "
1646 					    "overflow size_t",
1647 					    (long long)delta_data_offset);
1648 				}
1649 
1650 				mapoff = delta_data_offset;
1651 				err = got_inflate_to_mem_mmap(&base_buf,
1652 				    &base_bufsz, NULL, NULL, pack->map,
1653 				    mapoff, pack->filesize - mapoff);
1654 			} else {
1655 				if (lseek(pack->fd, delta_data_offset, SEEK_SET)
1656 				    == -1) {
1657 					err = got_error_from_errno("lseek");
1658 					goto done;
1659 				}
1660 				err = got_inflate_to_mem_fd(&base_buf,
1661 				    &base_bufsz, NULL, NULL, max_size,
1662 				    pack->fd);
1663 			}
1664 			if (err)
1665 				goto done;
1666 			n++;
1667 			continue;
1668 		}
1669 
1670 		if (pack->delta_cache) {
1671 			got_delta_cache_get(&delta_buf, &delta_len,
1672 			    pack->delta_cache, delta->data_offset);
1673 		}
1674 		if (delta_buf == NULL) {
1675 			cached = 0;
1676 			err = read_delta_data(&delta_buf, &delta_len, NULL,
1677 			    delta->data_offset, pack);
1678 			if (err)
1679 				goto done;
1680 		}
1681 		if (pack->delta_cache && !cached) {
1682 			err = got_delta_cache_add(pack->delta_cache,
1683 			    delta->data_offset, delta_buf, delta_len);
1684 			if (err == NULL)
1685 				cached = 1;
1686 			else if (err->code != GOT_ERR_NO_SPACE) {
1687 				free(delta_buf);
1688 				goto done;
1689 			}
1690 		}
1691 
1692 		err = got_delta_get_sizes(&base_size, &result_size,
1693 		    delta_buf, delta_len);
1694 		if (err) {
1695 			if (!cached)
1696 				free(delta_buf);
1697 			goto done;
1698 		}
1699 		if (base_size > max_size)
1700 			max_size = base_size;
1701 		if (result_size > max_size)
1702 			max_size = result_size;
1703 
1704 		if (max_size > base_bufsz) {
1705 			uint8_t *p = realloc(base_buf, max_size);
1706 			if (p == NULL) {
1707 				err = got_error_from_errno("realloc");
1708 				if (!cached)
1709 					free(delta_buf);
1710 				goto done;
1711 			}
1712 			base_buf = p;
1713 			base_bufsz = max_size;
1714 		}
1715 
1716 		if (max_size > accum_bufsz) {
1717 			uint8_t *p = realloc(accum_buf, max_size);
1718 			if (p == NULL) {
1719 				err = got_error_from_errno("realloc");
1720 				if (!cached)
1721 					free(delta_buf);
1722 				goto done;
1723 			}
1724 			accum_buf = p;
1725 			accum_bufsz = max_size;
1726 		}
1727 
1728 		err = got_delta_apply_in_mem(base_buf, base_bufsz,
1729 		    delta_buf, delta_len, accum_buf,
1730 		    &accum_size, max_size);
1731 		if (!cached)
1732 			free(delta_buf);
1733 		n++;
1734 		if (err)
1735 			goto done;
1736 
1737 		if (n < deltas->nentries) {
1738 			/* Accumulated delta becomes the new base. */
1739 			uint8_t *tmp = accum_buf;
1740 			size_t tmp_size = accum_bufsz;
1741 			accum_buf = base_buf;
1742 			accum_bufsz = base_bufsz;
1743 			base_buf = tmp;
1744 			base_bufsz = tmp_size;
1745 		}
1746 	}
1747 
1748 done:
1749 	free(base_buf);
1750 	if (err) {
1751 		free(accum_buf);
1752 		*outbuf = NULL;
1753 		*outlen = 0;
1754 	} else {
1755 		*outbuf = accum_buf;
1756 		*outlen = accum_size;
1757 	}
1758 	return err;
1759 }
1760 
1761 const struct got_error *
1762 got_packfile_extract_object(struct got_pack *pack, struct got_object *obj,
1763     FILE *outfile, FILE *base_file, FILE *accum_file)
1764 {
1765 	const struct got_error *err = NULL;
1766 
1767 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1768 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1769 
1770 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1771 		if (obj->pack_offset >= pack->filesize)
1772 			return got_error(GOT_ERR_PACK_OFFSET);
1773 
1774 		if (pack->map) {
1775 			size_t mapoff;
1776 
1777 			if (obj->pack_offset > SIZE_MAX) {
1778 				return got_error_fmt(GOT_ERR_RANGE,
1779 				    "pack offset %lld would overflow size_t",
1780 				    (long long)obj->pack_offset);
1781 			}
1782 
1783 			mapoff = obj->pack_offset;
1784 			err = got_inflate_to_file_mmap(&obj->size, NULL, NULL,
1785 			    pack->map, mapoff, pack->filesize - mapoff,
1786 			    outfile);
1787 		} else {
1788 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1789 				return got_error_from_errno("lseek");
1790 			err = got_inflate_to_file_fd(&obj->size, NULL, NULL,
1791 			    pack->fd, outfile);
1792 		}
1793 	} else
1794 		err = got_pack_dump_delta_chain_to_file(&obj->size,
1795 		    &obj->deltas, pack, outfile, base_file, accum_file);
1796 
1797 	return err;
1798 }
1799 
1800 const struct got_error *
1801 got_packfile_extract_object_to_mem(uint8_t **buf, size_t *len,
1802     struct got_object *obj, struct got_pack *pack)
1803 {
1804 	const struct got_error *err = NULL;
1805 
1806 	if ((obj->flags & GOT_OBJ_FLAG_PACKED) == 0)
1807 		return got_error(GOT_ERR_OBJ_NOT_PACKED);
1808 
1809 	if ((obj->flags & GOT_OBJ_FLAG_DELTIFIED) == 0) {
1810 		if (obj->pack_offset >= pack->filesize)
1811 			return got_error(GOT_ERR_PACK_OFFSET);
1812 		if (pack->map) {
1813 			size_t mapoff;
1814 
1815 			if (obj->pack_offset > SIZE_MAX) {
1816 				return got_error_fmt(GOT_ERR_RANGE,
1817 				    "pack offset %lld would overflow size_t",
1818 				    (long long)obj->pack_offset);
1819 			}
1820 
1821 			mapoff = obj->pack_offset;
1822 			err = got_inflate_to_mem_mmap(buf, len, NULL, NULL,
1823 			    pack->map, mapoff, pack->filesize - mapoff);
1824 		} else {
1825 			if (lseek(pack->fd, obj->pack_offset, SEEK_SET) == -1)
1826 				return got_error_from_errno("lseek");
1827 			err = got_inflate_to_mem_fd(buf, len, NULL, NULL,
1828 			    obj->size, pack->fd);
1829 		}
1830 	} else
1831 		err = got_pack_dump_delta_chain_to_mem(buf, len, &obj->deltas,
1832 		    pack);
1833 
1834 	return err;
1835 }
1836 
1837 static const struct got_error *
1838 read_raw_delta_data(uint8_t **delta_buf, size_t *delta_len,
1839     size_t *delta_len_compressed, uint64_t *base_size, uint64_t *result_size,
1840     off_t delta_data_offset, struct got_pack *pack, struct got_packidx *packidx)
1841 {
1842 	const struct got_error *err = NULL;
1843 
1844 	/* Validate decompression and obtain the decompressed size. */
1845 	err = read_delta_data(delta_buf, delta_len, delta_len_compressed,
1846 	    delta_data_offset, pack);
1847 	if (err)
1848 		return err;
1849 
1850 	/* Read delta base/result sizes from head of delta stream. */
1851 	err = got_delta_get_sizes(base_size, result_size,
1852 	    *delta_buf, *delta_len);
1853 	if (err)
1854 		goto done;
1855 
1856 	/* Discard decompressed delta and read it again in compressed form. */
1857 	free(*delta_buf);
1858 	*delta_buf = malloc(*delta_len_compressed);
1859 	if (*delta_buf == NULL) {
1860 		err = got_error_from_errno("malloc");
1861 		goto done;
1862 	}
1863 	if (pack->map) {
1864 		if (delta_data_offset >= pack->filesize) {
1865 			err = got_error(GOT_ERR_PACK_OFFSET);
1866 			goto done;
1867 		}
1868 		memcpy(*delta_buf, pack->map + delta_data_offset,
1869 		    *delta_len_compressed);
1870 	} else {
1871 		ssize_t n;
1872 		if (lseek(pack->fd, delta_data_offset, SEEK_SET) == -1) {
1873 			err = got_error_from_errno("lseek");
1874 			goto done;
1875 		}
1876 		n = read(pack->fd, *delta_buf, *delta_len_compressed);
1877 		if (n < 0) {
1878 			err = got_error_from_errno("read");
1879 			goto done;
1880 		} else if (n != *delta_len_compressed) {
1881 			err = got_error(GOT_ERR_IO);
1882 			goto done;
1883 		}
1884 	}
1885 done:
1886 	if (err) {
1887 		free(*delta_buf);
1888 		*delta_buf = NULL;
1889 		*delta_len = 0;
1890 		*delta_len_compressed = 0;
1891 		*base_size = 0;
1892 		*result_size = 0;
1893 	}
1894 	return err;
1895 }
1896 
1897 const struct got_error *
1898 got_packfile_extract_raw_delta(uint8_t **delta_buf, size_t *delta_size,
1899     size_t *delta_compressed_size, off_t *delta_offset,
1900     off_t *delta_data_offset, off_t *base_offset,
1901     struct got_object_id *base_id, uint64_t *base_size, uint64_t *result_size,
1902     struct got_pack *pack, struct got_packidx *packidx, int idx)
1903 {
1904 	const struct got_error *err = NULL;
1905 	off_t offset;
1906 	uint8_t type;
1907 	uint64_t size;
1908 	size_t tslen, delta_hdrlen;
1909 
1910 	*delta_buf = NULL;
1911 	*delta_size = 0;
1912 	*delta_compressed_size = 0;
1913 	*delta_offset = 0;
1914 	*delta_data_offset = 0;
1915 	*base_offset = 0;
1916 	*base_size = 0;
1917 	*result_size = 0;
1918 
1919 	offset = got_packidx_get_object_offset(packidx, idx);
1920 	if (offset == -1)
1921 		return got_error(GOT_ERR_BAD_PACKIDX);
1922 
1923 	if (offset >= pack->filesize)
1924 		return got_error(GOT_ERR_PACK_OFFSET);
1925 
1926 	err = got_pack_parse_object_type_and_size(&type, &size, &tslen,
1927 	    pack, offset);
1928 	if (err)
1929 		return err;
1930 
1931 	if (tslen + size < tslen || offset + size < size ||
1932 	    tslen + offset < tslen)
1933 		return got_error(GOT_ERR_PACK_OFFSET);
1934 
1935 	switch (type) {
1936 	case GOT_OBJ_TYPE_OFFSET_DELTA:
1937 		err = got_pack_parse_offset_delta(base_offset, &delta_hdrlen,
1938 		    pack, offset, tslen);
1939 		if (err)
1940 			return err;
1941 		break;
1942 	case GOT_OBJ_TYPE_REF_DELTA:
1943 		err = got_pack_parse_ref_delta(base_id, pack, offset, tslen);
1944 		if (err)
1945 			return err;
1946 		delta_hdrlen = SHA1_DIGEST_LENGTH;
1947 		break;
1948 	default:
1949 		return got_error_fmt(GOT_ERR_OBJ_TYPE,
1950 		    "non-delta object type %d found at offset %lld",
1951 		    type, (long long)offset);
1952 	}
1953 
1954 	if (tslen + delta_hdrlen < delta_hdrlen ||
1955 	    offset + delta_hdrlen < delta_hdrlen)
1956 		return got_error(GOT_ERR_BAD_DELTA);
1957 
1958 	*delta_data_offset = offset + tslen + delta_hdrlen;
1959 	err = read_raw_delta_data(delta_buf, delta_size, delta_compressed_size,
1960 	    base_size, result_size, *delta_data_offset, pack, packidx);
1961 	if (err)
1962 		return err;
1963 
1964 	if (*delta_size != size) {
1965 		err = got_error(GOT_ERR_BAD_DELTA);
1966 		goto done;
1967 	}
1968 
1969 	*delta_offset = offset;
1970 done:
1971 	if (err) {
1972 		free(*delta_buf);
1973 		*delta_buf = NULL;
1974 		*delta_size = 0;
1975 		*delta_compressed_size = 0;
1976 		*delta_offset = 0;
1977 		*base_offset = 0;
1978 		*base_size = 0;
1979 		*result_size = 0;
1980 	}
1981 	return err;
1982 }